The graph shows the function f(x) = 3x. What is the value of f –1(x) at x = 3? In the xy plane, the range of the x axis is zero to four by increment of one. The range of y axis is zero to fifty by increment of five. On the x axis two, four are labeled. On the y axis ten, twenty, thirty, and forty are labeled. The curve is passes through the points (0,1), (1, 3), (2,9), and (3,27). All points are labeled.

A. 0
B. 1
C. 3
D. 27